Chapter L: INCURVATUS, Trin. Much branched, decumbent, 6' high or less; spikes

terminal and lateral, 1--4' long, the base included in the broad sheath.--Borders of brackish marshes, Md. to S. Va., and on ballast northward. (Nat. from Eu.)

74. HORDEUM, Tourn. BARLEY. (Pl. 11.)

Spikelets 1-flowered, with an awl-shaped rudiment on the inner side, three at each joint of the rhachis of a terminal spike, but the lateral ones usually imperfect or abortive, and short-stalked. Empty glumes side by side in front of the spikelets, 6 in number, forming a kind of involucre, slender and awn-pointed or bristle-form. Flowering glume and palet herbaceous, the former (anterior) convex, long-awned from the apex. Stamens 3. Grain oblong, commonly adherent.--Spike often separating into joints. Ours annuals or biennials, or scarcely perennial. (The ancient Latin name.)

1. H. jubatum, L. (SQUIRREL-TAIL GRASS.) (Pl. 11, fig. 1, 2.) Low; lateral flowers abortive, on a short pedicel, short-awned; the perfect flower bearing a capillary awn (2' long) about equalling the similar capillary glumes, all spreading.--Sandy sea-shore, upper Great Lakes, and westward. June.

2. H. pratense, Huds. Low (6--18' high); lateral flowers imperfect or neutral, awnless or merely pointed; perfect flower with awn as long as those of the glumes (3--6''); spike linear, 1--2' long.--Plains, especially in saline soil, Ohio to Ill. and westward; also sparingly introduced, Va., and southward along the coast. May, June. (Eu.)

75. ELYMUS, L. LYME-GRASS. WILD RYE. (Pl. 11.)

Spikelets 2--4 at each joint of the rhachis of a terminal spike, all fertile and alike, sessile, each 1--7-flowered. Glumes conspicuous, nearly side by side in front of the spikelets, 2 for each spikelet, forming an involucre to the cluster. Flower coriaceous; the glume rounded on the back, acute or awned at the apex. Grain adherent to the involving glume (whence the name, an ancient one for some grain, from [Greek: e)lyo], _to roll up_).

[*] _Glumes and flowers firm or rigid, all or only the latter awned; spikelets 1--5-flowered; slender perennials, with rather harsh and broad flat leaves._

[+] _Spike large and stout._

1. E. Virginicus, L. (Pl. 11, fig. 1--3.) Culm stout, 2--3 deg. high; _spike rigidly upright, dense_ (2--3' long, 6'' thick), the short _peduncle usually included in the sheath_; spikelets 2--3 together, 2--3-flowered, smooth, rather short-awned, about the length of the thickened strongly-nerved and bristle-pointed _lanceolate glumes_.--River-banks; common. Aug.

2. E. Canadensis, L. _Spike soon nodding_ (5--9' long), on an exserted peduncle; spikelets mostly in pairs, of 3--5 long-awned rough or rough-hairy flowers; the _awl-shaped glumes tipped with shorter awns_.--Var. GLAUCIFOLIUS, Gray, is pale or glaucous throughout, the flowers with more spreading awns (11/2' long).--Var. INTERMEDIUS, Vasey, has the awns scarcely longer than the glumes.--River-banks; common.

[+][+] _Spike and culm more slender._

3. E. striatus, Willd. More or less _pubescent; spike dense and thickish_ (2--4' long), upright or slightly nodding; spikelets mostly in pairs, 1--2- (or rarely 3-) flowered, minutely bristly-hairy; _glumes awl-shaped, bristle-awned_, 1--3-nerved, _about thrice the length of the flowers_, which are only 3'' long exclusive of the capillary awn (1' long).--Var. VILLOSUS, Gray, has very hairy flowers and glumes, and villous sheaths.--Rocky woods and banks. July, Aug.

4. E. Sibiricus, L., var. Americanus. _Glabrous; spike wand-like_ (2--6' long, 2--3'' thick), often somewhat nodding; spikelets in pairs, 3--6-flowered; _glumes linear-lanceolate_, 3--5-nerved, acuminate and smooth or often scabrous on the nerves, _short-awned, shorter than the flowers_, which bear an erect awn of once or twice their length.--Marquette, Mich. (_Porter_), N. Minn., and westward.

[*][*] _Glumes and palet awnless and soft in texture; reed-like perennials_.

5. E. mollis, Trin. Culm (3 deg. high) velvety at top; spike thick, erect (8' long); spikelets 2 or 3 at each joint, 5--8-flowered; the lanceolate pointed 5--7-nerved glumes (1' long) and the pointed flowers soft-villous; rhachis of the spikelets separating into joints.--Shore of the Great Lakes, Maine, and northward. (Near E. arenarius.)

[*][*][*] _Empty glumes very narrow, and all very long-awned; spike disarticulating at maturity._

6. E. Sitanion, Schultes. Low (1/2--2 deg. high), stout; spike 1--4' long, the peduncle slightly exserted; the spreading scabrous awns 2--3' long.--Central Minn. to Kan., and westward.

76. ASPRELLA, Willd. BOTTLE-BRUSH GRASS. (Pl. 11.)

Spikelets 2--3 or sometimes solitary on each joint of the rhachis of a terminal spike, raised on a very short callous pedicel, loosely 2--4-flowered (when solitary flatwise on the rhachis). Glumes none! or small, awn-like, and deciduous. Otherwise nearly as in Elymus. (Name a diminutive of _asper_, rough or prickly.)

1. A. Hystrix, Willd. Perennial; culms 3--4 deg. high; leaves and sheaths smoothish; spike loose (3--6' long); the spreading spikelets 2--3 together, early deciduous; flowers smoothish or often rough-hairy, tipped with an awn thrice their length (1' long). (Gymnostichum Hystrix, _Schreb._)--Moist woodlands. July, Aug.

77. ARUNDINARIA, Michx. CANE. (Pl. 11.)

Spikelets flattened, 5--14-flowered; the flowers somewhat separated on the jointed rhachis. Empty glumes very small, membranaceous, the upper one larger. Flowering glumes and palet herbaceous or somewhat membranaceous, the glume convex on the back, many-nerved, tapering into a mucronate point or bristle. Squamulae 3, longer than the ovary. Stamens 3. Grain oblong, free.--Arborescent or shrubby grasses, simple or with fascicled branches, and with large spikelets in panicles or racemes; blade of the leaf jointed upon the sheath; flowers polygamous. (Name from _arundo_, a reed.)

1. A. macrosperma, Michx. (LARGE CANE.) (Pl. 11, fig. 1, 2.) Culms arborescent, 10--40 deg. high and {1/2}--3' thick at base, rigid, simple the first year, branching the second, afterwards at indefinite periods fruiting, and soon after decaying; leaves lanceolate (1--2' wide), smoothish or pubescent, the sheath ciliate on one margin, stoutly fimbriate each side of the base of the leaf; panicle lateral, composed of few simple racemes; spikelets 1--3' long, purplish or pale, erect; flowering glume lanceolate, acute or acuminate, glabrous or pubescent, fringed (5--12'' long).--River-banks, S. Va.(?), Ky., and southward, forming cane-brakes. April.

Var. suffruticosa, Munro. (SWITCH CANE. SMALL CANE.) Lower and more slender (2--10 deg. high), often growing in water; leaves 4''--1' broad; spikelets solitary or in a simple raceme at the summit of the branches, or frequently on leafless radical culms. (A. tecta, _Muhl._)--Swamps and moist soil, Md., S. Ind. to S. E. Mo., and southward. Sometimes fruiting several years in succession.

SERIES II.

CRYPTOGAMOUS OR FLOWERLESS PLANTS.

Vegetables destitute of proper flowers (i.e. having no stamens nor pistils), and producing instead of seeds minute one-celled germinating bodies called _spores_, in which there is no embryo or rudimentary plantlet.

CLASS III. ACROGENS.

Cryptogamous plants with a distinct axis or stem, growing from the apex, and commonly not with later increase in diameter, usually furnished with distinct leaves; reproduction by antheridia and archegonia, sometimes also by gemmation.

SUBCLASS I. VASCULAR ACROGENS, OR PTERIDOPHYTES.[1]

[Footnote 1: The orders of this Subclass have been elaborated anew for this edition by Prof. DANIEL C. EATON of Yale University.]

Stems containing woody fibre and vessels (especially scalariform or spiral ducts). Antheridia or archegonia, or both, formed on a minute prothallus which is developed from the spore on germination, the archegonium containing a nucleus, which after fertilization becomes an oospore and at length grows into the conspicuous spore-bearing plant.

ORDER 130. EQUISETACEAE. (HORSETAIL FAMILY.)

_Rush-like, often branching plants, with jointed and mostly hollow stems from running rootstocks, having sheaths at the joints, and, when fertile, terminated by the conical or spike-like fructification composed of shield-shaped stalked scales bearing the spore-cases beneath._--A single genus.

1. EQUISETUM, L. HORSETAIL. SCOURING RUSH. (Pl. 21)

Spore-cases (_sporangia, thecae_) 6 or 7, adhering to the under side of the angled shield-shaped scales of the spike, 1-celled, opening down the inner side and discharging the numerous loose spores. To the base of each spore are attached 4 thread-like and club-shaped elastic filaments, which roll up closely around the spore when moist, and uncoil when dry.--Rootstocks perennial, wide-creeping, hard and blackish, jointed, often branched and sometimes bearing small tubers. Stems erect, cylindrical, hollow, jointed; the surface striated or grooved with alternate ridges and furrows, the cuticle in most species containing silica in the form of minute granules, rosettes, or tubercles; the joints containing besides the central air-cavity a circle of smaller hollows beneath the furrows and a set of still smaller ones beneath the ridges; the nodes closed and solid, each bearing instead of leaves a sheath which is divided into teeth corresponding in number and position to the principal ridges of the stem; stomata in the furrows, each with two pairs of guard-cells, of which the outer pair is marked with radiating lines of silica. Branches, when present, in whorls from the base of the sheath, like the stem, but without the central air-cavity. Prothallus green, formed upon the ground, often variously lobed, usually dioecious. (The ancient name, from _equus_, horse, and _seta_, bristle.)

Sec. 1. _Annual-stemmed, not surviving the winter._

[*] _Fruiting in spring from soft and rather succulent pale or brownish fertile stems, the sterile stems or branches appearing later, herbaceous and very different._

[+] _Fertile stems unbranched, destitute of chlorophyll and soon perishing; the sterile branching copiously._

1. E. arvense, L. (COMMON H.) Fertile stems (4--10' high) with loose and usually distant about 8--12-toothed sheaths; the sterile slender (at length 1--2 deg. high), 10--14-furrowed, producing long and simple or sparingly branched 4-angular branches, their teeth 4, herbaceous, lanceolate.--Moist, especially gravelly soil; very common. March--May. Rootstocks often bearing little tubers.--Var. CAMPESTRE, Milde, is a not uncommon state, in which the sterile stem bears a small fruiting spike at the summit. (Eu.)

[+][+] _Fertile stems when older producing herbaceous 3-sided branches, and lasting through the summer, except the naked top which perishes after fructification._

2. E. pratense, Ehrh. Sterile and finally also the fertile stems producing _simple straight branches_; sheaths of the stem with ovate-lanceolate short teeth, those of the branches 3-toothed; stems more slender and the branches shorter than in the last.--Mich. to Minn., and northward. April, May. (Eu.)

3. E. sylvaticum, L. Sterile and fertile stems (about 12-furrowed) producing _compound racemed branches_; sheaths loose, with 8--14 rather blunt teeth, those of the branches bearing 4 or 5, of the branchlets 3, lance-pointed divergent teeth.--Wet shady places; common northward. May. (Eu.)

[*][*] _Fruiting in summer; stems all of one kind, or the fertile contemporaneous with and like the sterile, equally herbaceous, producing mostly simple branches, or sometimes nearly naked._

4. E. palustre, L. Stems (10--18' high) slender, very deeply 5--9-grooved, _the ridges narrow and acute_, roughish, the lance-awl shaped teeth whitish-margined; branches always hollow, 4--7-angled, rather few in a whorl.--Wet places, Niagara River (_Clinton_), Wisc. (_Austin_), and northward. June. (Eu.)

5. E. littorale, Kuehlewein. Stems (8--18' high) slender, deeply 6--16-grooved, _the ridges rounded_, the teeth shorter than in the last, narrowly white-margined; branches often solid, 3--4-angled, 2--6 in a whorl.--Wet sandy shores, Vt. and N. Y., and northward.--Spores always abortive, whence the plant has been considered a hybrid, perhaps of E. arvense and E. limosum. July. (Eu.)

6. E. limosum, L. (Pl. 21, fig. 1--5.) Stems (2--5 deg. high) _slightly many-furrowed_, smooth, sometimes continuing unbranched, but usually producing ascending branches after fructification; sheaths appressed, with 10--22 (commonly about 18) dark-brown and acute rigid short teeth.--In shallow water; rather common.--Air-cavities none under the grooves, but small ones under the ridges. A form in which the branches bear numerous small spikes is var. POLYSTACHYUM, Brueckner. June, July. (Eu.)

Sec. 2. _Stems all alike, evergreen, unbranched, or producing a few slender erect branches; fruiting in summer. Central air-cavity of the stem very large._

[*] _Stems tall and stout (1{1/2}--4 deg. or even 6 deg. high), simple, or casually branched, evenly many-grooved; sheaths appressed._

7. E. hyemale, L. (SCOURING-RUSH. SHAVE-GRASS.) Stems 1{1/2}--4 deg. high, 8--34 grooved, the _ridges_ roughened by two more or less distinct lines of _tubercles; sheaths elongated_, with a black girdle above the base and a black limb; ridges of the sheaths obscurely 4-carinate, the teeth blackish, membranaceous, soon falling off.--Wet banks; common northward. Formerly in common use for polishing wood and metal. (Eu.)

8. E. robustum, Braun. Stems tall and stout (sometimes 8--10 deg. high and nearly an inch thick), 20--48-grooved, the _ridges_ roughened _with one line of transversely oblong tubercles; sheaths rather short_, with a black girdle at base and a black limb; ridges of the sheaths tricarinate, the blackish teeth soon falling off.--River-banks, Ohio and westward.

9. E. laevigatum, Braun. Stems 1--4 deg. high, rather slender, pale green, 14--30-grooved, the ridges almost smooth; sheath slightly enlarged upward, with a black girdle at the base of the mostly deciduous white-margined teeth, and rarely also at the base of the sheath; ridges of the sheath with one keel, or sometimes obscurely tricarinate.--By streams and in clayey places, Ohio to Minn., and westward.

[*][*] _Stems slender, in tufts, 5--10-grooved; sheaths looser._

10. E. variegatum, Schleicher. _Stems ascending_ (6--18' long), usually simple from a branched base, _5--10-grooved_; sheaths green variegated with black above, the 5--10 teeth tipped with a deciduous bristle.--Shores or river-banks, N. H. (Bellows Falls, _Carey_) and Niagara to Minn., and northward; rare. (Eu.)

11. E. scirpoides, Michx. _Stems very numerous in a tuft, filiform_ (3--6' high), _flexuous and curving, mostly 6-grooved_, with acute ridges; _sheaths 3-toothed_, the bristle-pointed teeth more persistent; central air-cavity wanting.--Wooded hillsides, N. Eng. to Penn., Minn., and northward. (Eu.)

ORDER 131. FILICES. (FERNS.)

_Leafy plants, with the leaves_ (fronds) _usually raised on a stalk or petiole_ (stipe), _rising from a_ (sometimes greatly elongated) _rootstock, separately rolled up_ (circinate) _in the bud, and bearing on the under surface or along the margin small reticulated sporangia, which at length split open and discharge the numerous minute spores. Prothallus green, above ground, normally monoecious._

SUBORDER I. Polypodiaceae. Sporangia collected in dots, lines, or variously shaped clusters (_sori_ or _fruit-dots_) on the back or margins of the frond or its divisions, cellular-reticulated, stalked, the stalk running into a vertical incomplete many-jointed ring, which by straightening at maturity ruptures the sporangium transversely on the inner side, discharging the spores. Fruit dots often covered (at least when young) by a membrane called the _indusium_ (or less properly the _involucre_), growing either from the back or the margin of the frond. (Plates 16--19.)

Tribe I. POLYPODIEAE. Fructification on the back of the frond, in round or roundish fruit-dots (_sori_) placed on the veins or at the ends of the veins, without indusium of any kind. Stipes articulated to the rootstock, leaving a distinct scar when separated. Veins free (not reticulated) in our species.

1. Polypodium. Sori round, in one or more rows, on each side of the midrib or of the segments of the frond.

Tribe II. GRAMMITIDEAE. Sori more or less elongated, without indusium, placed on the back of the frond, usually along the veins or near their extremities. Veins free in our species.

2. Notholaena. Sori short, of few rather large sporangia, placed near the tips of the veins; under surface of the frond usually either chaffy, woolly, or powdery.

Tribe III. PTERIDEAE. Fructification marginal or intramarginal, provided with a general indusium formed of the (either altered or unchanged) margin of the frond. Stipes not articulated to the rootstock. Veins free in all our species.

[*] Sporangia at the ends of the veins, on a reflexed portion of the margin of the frond.

3. Adiantum. Midrib of the pinnules marginal or none. Stipe black and polished.

[*][*] Sporangia borne on a continuous marginal vein-like receptacle, connecting the apices of the veins, and covered by a delicate whitish indusium formed of the reflexed margin.

4. Pteris. Midrib of the pinnules central. Stipe light colored.

[*][*][*] Sporangia at or near the ends of the unconnected veins, borne on the under surface of the frond; indusium various.

5. Cheilanthes. Sori minute, at the ends of the veins; indusium continuous or interrupted. Fronds mostly chaffy, woolly, or pulverulent, rarely smooth.

6. Pellaea. Sori on the upper part of the veins, distinct, or mostly forming a confluent submarginal band of sporangia. Indusium membranaceous, continuous, rarely wanting. Sterile and fertile fronds not very unlike; stipes dark colored; fronds smooth.

7. Cryptogramme. Sori roundish or elongated and extending far down the free veins, at first covered by the very broad continuous indusium, at length exposed and confluent. Sterile and fertile fronds very different; stipes light colored; fronds smooth.

Tribe IV. BLECHNEAE. Sori oblong or linear, borne on a veinlet parallel to the midrib, and covered with a special usually concave or arched indusium attached to the fruiting veinlet, and opening along the inner side.

8. Woodwardia. Sori forming a chain-like row each side of the midrib or central vein. Veins reticulated.

Tribe V. ASPLENIEAE. Sori more or less elongated, occupying one or both sides of oblique veins, covered by a special indusium which is attached by one side to the fertile vein, and is free on the other. Stipes not articulated.

9. Asplenium. Sori on the upper side or rarely on both sides of a veinlet. Veins free in all our species.

10. Scolopendrium. Sori linear, confluent in pairs, each pair appearing like a single sorus with a double indusium opening down the middle. Veins free.

11. Camptosorus. Sori oblong, variously curved, or some of them in opposite pairs. Veins reticulated.

Tribe VI. ASPIDIEAE. Sori round or roundish, on the back or rarely at the apex of the vein, with a special indusium, rarely naked. Stipes not articulated to the rootstock.

[*] Indusium obsolete or none.

12. Phegopteris. Sori round, rather small. Veins free in our species.

[*][*] Indusium evident, round or roundish, covering the sporangia, at least when young. Sterile and fertile fronds not very unlike. Veins free in our species.

13. Aspidium. Indusium flat or slightly convex, orbicular or round-reniform, fixed by the centre, opening all round the margin.

14. Cystopteris. Indusium convex, fixed by a broad base partly under the sorus, commonly reflexed as the sporangia ripen.

[*][*][*] Indusium obscure, irregularly semicircular. Fertile fronds much contracted and very unlike the sterile ones.

15. Onoclea. Sporangia on an elevated receptacle; divisions of the fertile frond pod-like or berry-like.

Tribe VII. WOODSIEAE. Sori round, borne on the veins; indusium fixed under the sorus, divided into segments or into slender filaments.

16. Woodsia. Small ferns with free veins. Indusium very delicate.

Tribe VIII. DICKSONIEAE. Sori roundish, marginal or submarginal. Indusium cup-shaped or two-valved, the outer portion composed of a reflexed lobule of the frond, or more or less united to it.

17. Dicksonia. Indusium in our species small, membranaceous, nearly globular. Frond elongated, decompound.

SUBORDER II. Hymenophyllaceae. Sporangia sessile on a bristle-like receptacle within a cup-shaped or bivalvular involucre, the ring transverse and complete. Fronds delicately membranaceous.

18. Trichomanes. Involucres funnel-form or cup-shaped.

SUBORDER III. Schizaeaceae. Sporangia ovate, sessile, having a complete transverse articulated ring at the apex, and opening by a longitudinal slit. (Pl. 19.)

19. Schizaea. Sporangia naked, fixed in a double row to the midrib of the narrow fertile segments. Sterile fronds rigid, simple or dichotomously branched.

20. Lygodium. Sporangia borne in a double row on narrow fertile segments, each sporangium seated on a separate veinlet, and provided with a special scale-like indusium. Fronds leafy, climbing.

SUBORDER IV. Osmundaceae. Sporangia naked, globose, mostly pedicelled, reticulated, with no ring or mere traces of one near the apex, opening into two valves by a longitudinal slit. Stipes winged at base and almost stipulate! (Pl. 19.)

21. Osmunda. Fertile pinnae or fronds very much contracted, bearing the abundant and large sporangia upon the margins of the very narrow segments. Veins free.

1. POLYPODIUM, L. POLYPODY. (Pl. 16.)

Fruit-dots round, naked, arranged on the back of the frond in one or more rows each side of the midrib or central vein, or irregularly scattered, each borne in our species on the end of a free veinlet. Rootstocks creeping, branched, often covered with chaffy scales, bearing scattered roundish knobs, to which the stipes are attached by a distinct articulation. (Name from [Greek: poly/s], _many_, and [Greek: pou~s], _foot_, alluding to the branching rootstock.)

1. P. vulgare, L. (Pl. 16, fig. 1--3.) Fronds evergreen, oblong, _smooth both sides_, 4--10' high, simple and deeply pinnatifid; the divisions linear-oblong, obtuse or somewhat acute, remotely and obscurely toothed; veins once or twice forked; _fruit-dots large, midway between the midrib and the margin_.--Rocks; common. July. (Eu.)

2. P. incanum, Swartz. Fronds evergreen and coriaceous, oblong, 2--6' high, _grayish and very scurfy underneath with peltate scales_, simply pinnatifid; the divisions oblong-linear, obtuse; _fruit-dots rather small, near the margin_; veins forking, free in the N. American plant!--Rocks and trunks of trees, Va. and Ohio to Ill., and southward. Aug.

2. NOTHOLAENA, R. Brown. CLOAK-FERN.

Fruit-dots roundish or oblong, placed near the ends of the veins, soon more or less confluent into an irregular marginal band, with no proper involucre. Veins always free. Fronds of small size, 1--4-pinnate, the lower surface almost always either hairy, tomentose, chaffy, or covered with a fine waxy white or yellow powder. (Name from [Greek: no/thos], _spurious_, and [Greek: lai~na], _a cloak_, the woolly coating of the original species forming a spurious covering to the sporangia.)

1. N. dealbata, Kunze. Fronds triangular-ovate, 1--3' long, 3--4-pinnate; rhachis and branches straight, black and shining; ultimate pinnules scarcely a line long, white and powdery on the lower surface.--Clefts of calcareous rocks, Mo., Kan., and southwestward. July--Aug.

3. ADIANTUM, L. MAIDENHAIR. (Pl. 17.)

Fruit-dots marginal, short, borne on the under side of a transversely oblong, crescent-shaped or roundish, more or less altered margin or summit of a lobe or tooth of the frond reflexed to form an indusium; the sporangia attached to the approximated tips of the free forking veins.--Main rib (costa) of the pinnules none (in our species), or at the lower margin. Stipes black and polished. (The ancient name, from [Greek: a] privative and [Greek: diai/no], meaning _unwetted_, the smooth foliage repelling rain-drops.)

1. A. pedatum, L. (Pl. 17, fig. 1--3.) _Frond forked at the summit of the upright slender stalk_ (9--15' high), the recurved branches bearing on one side several slender spreading pinnate divisions; pinnules numerous, short-stalked and obliquely triangular-oblong, entire on the lower margin, from which the veins all proceed, and cleft and fruit-bearing on the other.--Rich, moist woods. July.--A delicate and most graceful Fern.

2. A. Capillus-Veneris, L. _Fronds with a continuous main rhachis, ovate-lanceolate_, 9--18' long, often pendent, 2--3-pinnate at the base, the upper third or half simply pinnate; pinnules wedge-obovate or rhomboid, 6--12'' long, deeply and irregularly incised; veinlets flabellately forking from the base; involucres lunulate or transversely oblong.--Moist rocky places, Va. to Mo., and southward. (Eu.)

4. PTERIS, L. BRAKE or BRACKEN. (Pl. 17.)

Sporangia in a continuous slender line of fructification, occupying the entire margin of the fertile frond, and covered by its reflexed narrow edge which forms a continuous membranaceous indusium, attached to an uninterrupted transverse vein-like receptacle connecting the tips of the forked free veins.--Fronds 1--3-pinnate or decompound. (The ancient Greek name of Ferns, from [Greek: ptero/n], _a wing_, on account of the prevalent pinnate or feathery fronds.)

1. P. aquilina, L. (COMMON BRAKE.) Frond dull green (2--3 deg. wide), ternate at the summit of an erect stout stalk (1--2 deg. high), the widely spreading branches twice pinnate; pinnules oblong-lanceolate; the upper undivided; the lower more or less pinnatifid, with oblong obtuse lobes, margined all round with the indusium, which is really double in this species.--Var. CAUDATA, with the lobes very narrow and revolute, the terminal ones much elongated, is a southern form, which extends in a modified condition as far north as New Jersey.--Thickets and hillsides, common. Aug. (Eu.)

5. CHEILANTHES, Swartz. LIP-FERN. (Pl. 17.)

Sporangia borne on the thickened ends of free veinlets, forming small and roundish distinct or nearly contiguous marginal fruit-dots, covered by a mostly whitish and membranaceous, sometimes herbaceous, common indusium, formed of the reflexed margin of separate lobes or of the whole pinnule.--Low, mostly with 2--3-pinnate and hairy or chaffy, rarely smooth fronds, the sterile and fertile nearly alike, the divisions with the principal vein central. Some species with continuous indusium connect this genus very closely with the next. (Name composed of [Greek: chei~los], _a lip_, and [Greek: a)/nthos], _flower_, from the shape of the indusium.)

[*] _Fronds smooth, or at most hairy._

1. C. Alabamensis, Kunze. _Fronds smooth_, chartaceous (2--8' long), ovate-lanceolate, bipinnate; pinnae numerous, oblong-lanceolate; pinnules triangular-oblong, rather acute, often auriculate or lobed; _indusium continuous, rather broad, pale, and of firm consistence_.--On rocks, mountains of Va. to Ky., and southward.

2. C. vestita, Swartz. (Pl. 17, fig. 1, 2.) Fronds (6--15' high), lanceolate-oblong, hirsute, as are the brown and shining stipes, with _straightish prominently articulated rusty hairs_, twice pinnate; pinnae rather distant, triangular-ovate; pinnules oblong, crowded (2--4'' long), more or less incised, _the ends of the roundish or oblong lobes reflexed and forming separate herbaceous involucres_, which are pushed back by the ripened sporangia.--Clefts of rocks, Manhattan Island (_W. W. Denslow_) and N. J. to Ill., and southward.

[*][*] _Fronds woolly or tomentose._

3. C. tomentosa, Link. Fronds (12--20' high) lanceolate-oblong, densely tomentose with _slender and entangled whitish obscurely articulated hairs_, thrice pinnate; primary and secondary pinnae oblong or ovate-oblong; _pinnules distinct_, minute (1/2--1'' long), roundish-obovate, sessile or adnate-decurrent, the upper surface less woolly, _the reflexed narrow margin forming a continuous somewhat membranaceous indusium_.--Mountains of Va. and Ky.; thence west and southward.--Stipe and rhachis rather stout, brown, covered with narrow chaffy scales and whitish hairs.

4. C. lanuginosa, Nutt. Stipes slender, at first hairy, black or brown, shining; fronds (3--6' high) ovate-lanceolate, woolly with _soft whitish distinctly articulated flattened hairs_, becoming smoother above, twice or thrice pinnate; pinnae (5--6'' long) ovate, the lowest distant, the others contiguous; _pinnules crenately pinnatifid_, or mostly divided into minute and roundish densely crowded segments (1/2--1'' long), _the herbaceous margin recurved forming an almost continuous indusium_.--In dense tufts, on dry rocks and cliffs, Ill. to Minn., thence west and southward.

6. PELLAEA, Link. CLIFF-BRAKE. (Pl. 16.)

Sporangia in roundish or elongated clusters on the upper part of the free veins, distinct, or confluent laterally so as to imitate the marginal continuous line of fructification of Pteris, commonly covered by a broad membranaceous and continuous (rarely interrupted) general indusium, which consists of the reflexed and altered margin of the fertile pinnule or division. Small ferns, with 1--3-pinnate fronds, the fertile ones with narrower divisions than the sterile, but otherwise similar. Stipes generally dark-colored, smooth and shining. (Name from [Greek: pello/s], _dusky_, alluding to the stipe.)

1. P. gracilis, Hook. (Pl. 16.) Fronds smooth (3--6' high), _delicately membranaceous and slender_, of few pinnae, the lower ones once or twice pinnately parted into 3--5 decurrent divisions, those of the fertile frond oblong or linear-oblong, entire or sparingly incised; of the sterile ovate or obovate, crenate or incised; veins of the fertile fronds mostly only once forked.--Shaded calcareous rocks, Mass. to Minn., and northward; rare. July.--Rootstock very slender, creeping; stipes polished, brownish, darker and sparingly chaffy at base.

2. P. atropurpurea, Link. Smooth, except some bristly-chaffy hairs on the midribs and especially on the _dark purple and polished stalk_ and rhachis, 6--15' high; _frond coriaceous_, pale, once or below twice pinnate; the divisions broadly linear or oblong, or the sterile sometimes oval, chiefly entire, somewhat heart-shaped or else truncate at the stalked base; veins about twice forked.--Dry calcareous rocks; not common, but of wide range. July.--Rootstock short and stout; stipes clustered.

7. CRYPTOGRAMME, R. Brown. ROCK-BRAKE.

Fruit-dots roundish or elongated and extending far down on the free forking veins. True involucre or indusium none, the herbaceous margins of the fertile segments at first reflexed and meeting at the midrib, at length opening out flat and exposing the confluent sporangia.--Low ferns, with smooth, 2--3-pinnate fronds, the fertile ones taller than the sterile, and with much narrower divisions. (Name from [Greek: krypto/s], _hidden_, and [Greek: gramme/], _a line_, alluding to the lines of sporangia at first concealed by the reflexed margin.)

1. C. acrostichoides, R. Brown. Stipes densely tufted, straw-colored; fronds 2--3-pinnate (6--10' high); fertile segments stalked, linear or linear-oblong (3--5'' long), the sporangia in lines extending down the veins almost to the midrib, confluent when ripe and covering the under surface of the now fully opened segments; sterile fronds on much shorter stipes, with ovate or obovate decurrent and crenately toothed or incised segments. (Allosorus acrostichoides, _Sprengel_.)--On rocks, from L. Superior westward and northward.--Very near C. crispa of Eu.

8. WOODWARDIA, Smith. CHAIN-FERN. (Pl. 17.)

Fruit-dots oblong or linear, arranged in one or more chain-like rows on transverse anastomosing veinlets parallel and near to the midrib. Indusium fixed by its outer margin to the fruitful veinlet, free and opening on the side next the midrib. Veins more or less reticulated, free toward the margin of the frond.--Large ferns, with pinnatifid or pinnate fronds. (Named for _Thomas J. Woodward_, an English botanist.)

Sec. 1. ANCHISTEA. _Sterile and fertile fronds alike; veins forming only one row of meshes (areoles)._

1. W. Virginica, Smith. (Pl. 17, fig. 4, 5.) Fronds (2--3 deg. high) pinnate, with numerous lanceolate pinnatifid pinnae; segments oblong; veins forming a row of narrow areoles along the midrib both of the pinnae and of the lobes, the outer veinlets free; fruit-dots oblong, one to each areole, confluent when ripe.--Wet swamps, Maine to Ark., and southward. Rootstocks creeping, often 6--8 deg. long! July.

Sec. 2. LORINSERIA. _Sterile and fertile fronds unlike; veins of the sterile fronds forming many rows of meshes._

2. W. angustifolia, Smith. (Pl. 17, fig. 1--3.) Fronds pinnatifid; sterile ones (12--18' high) with lanceolate serrulate divisions united by a broad wing; fertile fronds taller, with narrowly linear almost disconnected divisions, the areoles and fruit-dots (4--5'' long) in a single row each side of the secondary midribs; rootstocks creeping.--Wet woods, New Eng., near the coast, to Ark., and southward; rare. Aug., Sept.

9. ASPLENIUM, L. SPLEENWORT. (Pl. 18.)

Fruit-dots oblong or linear, oblique, separate; the straight, or rarely curved, indusium fixed lengthwise by one edge to the upper (inner) side of the fertile vein;--in some species a part of the fruit-dots are double, the fertile vein bearing two indusia placed back to back. Veins free in all our species. (Name from [Greek: a]- privative and [Greek: sple/n], _the spleen_, for supposed remedial properties.)

Sec. 1. ASPLENIUM proper. _Indusium straight or slightly curved, attached to the upper side of the vein, rarely double._

[*] _Small evergreen ferns; fronds pinnatifid, or pinnate only near the base._

1. A. pinnatifidum, Nutt. _Fronds_ (3--6' long) lanceolate, _pinnatifid, or pinnate below, tapering above into a slender prolongation_, "the apex sometimes rooting"; _lobes roundish-ovate, obtuse, or the lowest pair long-acuminate_; fruit-dots irregular, those next the midrib often double, even the slender prolongation fertile.--On cliffs and rocks, Penn. to Mo., and southward; very rare. July.--Resembles the Walking-Leaf (Camptosorus), but the veins are free. _Stipes brownish, becoming green above, and so passing into the broad pale green midrib._

2. A. ebenoides, R. R. Scott. _Fronds_ (4--9' long) broadly lanceolate _pinnatifid, below pinnate, the apex prolonged and slender; divisions lanceolate from a broad base, the lower ones shorter_, often proliferous, as is the apex of the frond; fruit-dots much as in the last; _stipes black and polished, as is the lower part of the midrib, especially beneath_.--Limestone cliffs, Conn. and Penn., and southward; very rare, usually growing with Camptosorus and Asplenium ebeneum, of which _Rev. M. G. Berkeley_ considered it a probable hybrid.

[*][*] _Small evergreen ferns; the narrow fronds simply pinnate with numerous pinnae._

[+] _Pinnae not auricled._

3. A. viride, Hudson. _Fronds_ (2--5' long) tufted, _linear in outline, pale green, softly herbaceous; pinnae roundish-ovate or ovate-rhomboid_, short-stalked, crenately toothed (2--4'' long), the midvein indistinct and forking; _the slender stipe brownish and passing into a green herbaceous rhachis_.--Shaded cliffs; northern New Eng., west and northward; rare. (Eu.)

4. A. Trichomanes, L. _Fronds_ (3--8' long) in dense spreading tufts, _linear in outline, dark green and more rigid; pinnae roundish-oblong or oval_ (3--4'' long), entire or crenulate, rarely incised, unequal-sided, obliquely wedge-truncate at base, attached by a narrow point, the midvein forking and evanescent; _the thread-like stipe and rhachis purple-brown and shining_.--Shaded cliffs; common. July. (Eu.)

[+][+] _Pinnae more or less auricled._

5. A. parvulum, Mart. & Gal. Fronds upright (4--10' high), narrowly linear-oblanceolate; _pinnae_ (2--6'' long) _rigid and thickish, mostly opposite_, nearly sessile, somewhat deflexed, oblong, obtuse, _entire or crenulate_, auricled on the upper or both sides; sori rather few, as near the margin as the continuous midvein; stipe and rhachis black and shining.--Mountains of Va. to Mo., and southward.--Nearly intermediate between the last and the next.

6. A. ebeneum, Ait. Fronds upright (9--18' high), linear-oblanceolate in outline, fertile ones much the taller; _pinnae_ (6--18'' long) _firmly membranaceous, mostly alternate_, sessile, spreading, oblong or oblong-linear, _finely serrate or even incised_, the base auricled on the upper or both sides; sori many, nearer the elongated midvein than the margin; stipe and rhachis blackish-purple and shining.--Rocky, open woods; rather common.

[*][*][*] _Small evergreen ferns; the broader fronds 1--3-pinnate; pinnae incised._

7. A. Bradleyi, D. C. Eaton. _Fronds oblong-lanceolate_, 4--7' long, besides the blackish and somewhat shining stipe, membranaceous, pinnate; pinnae rather numerous, _the lower ones no larger than the middle ones_, all short-stalked, oblong-ovate, obtuse, incised or pinnatifid into oblong toothed lobes.--On rocks, Ky. and southward; rare. A single plant has been gathered near Newburg, N. Y.--Intermediate between A. ebeneum and A. montanum.

8. A. montanum, Willd. _Fronds ovate-lanceolate from a broad base_ (2--5' long), subcoriaceous, pinnate; pinnae ovate-oblong, the lowest pinnately cleft into oblong or ovate cut-toothed lobes, the upper gradually simpler; _rhachis green, broad and flat; stipe brown at base_.--Cliffs and rocks, from Conn. and Penn. to Ky., and southward. July.

9. A. Ruta-muraria, L. _Fronds deltoid-ovate_ (1--21/2' long), subcoriaceous, laxly 2--3-pinnate at base, the pinnae alternate; _ultimate segments few_, stalked (2--5'' long), _from narrowly cuneate to roundish-obovate_, toothed or incised at the apex; veins forking; sori 2--4 on a segment.--Limestone cliffs, Vt. to Mich., and southward; scarce. July. (Eu.)

[*][*][*][*] _Tall ferns (2--4 deg. high), not evergreen; fronds pinnate or sub-bipinnate._

10. A. angustifolium, Michx. _Fronds_ thin, _simply pinnate; pinnae_ numerous, short-stalked, _linear-lanceolate, acuminate_, entire or crenulate (3--4' long), _those of the fertile frond narrower_; fruit-dots linear, 20--40 each side of the midvein; indusia slightly convex.--Rich woods, W. New Eng. to Wisc., and southward along the mountains. Sept.

11. A. thelypteroides, Michx. (Pl. 18, fig. 1, 2.) _Fronds_ (2--3 deg. high) _pinnate; pinnae deeply pinnatifid_, linear-lanceolate (3--5' long); the lobes oblong, obtuse, minutely toothed, crowded, each bearing 3--6 pairs of _oblong fruit-dots_, some of them double.--Rich woods; not rare. July--Sept.

Sec. 2. ATHYRIUM. _Indusium delicate, curved, often crossing the vein, and attached to both sides of it, thus becoming reniform, or shaped like a horseshoe._

12. A. Filix-foemina, Bernh. Fronds (1--3 deg. high) ovate-oblong or broadly lanceolate, twice pinnate; pinnae lanceolate, numerous; pinnules confluent on the secondary rhachis by a narrow margin, oblong and doubly serrate, or elongated and pinnately incised with cut-toothed segments; fruit-dots short, variously curved, at length confluent.--Moist woods; common and presenting many varying forms. July. (Eu.)

10. SCOLOPENDRIUM, Smith. HART'S-TONGUE. (Pl. 18.)

Fruit-dots linear, elongated, almost at right angles to the midrib, contiguous by twos, one on the upper side of one veinlet, and the next on the lower side of the next superior veinlet, thus appearing to have a double indusium opening along the middle. (The ancient Greek name, so called because the numerous parallel lines of fruit resemble the feet of the centipede, or _Scolopendra_.)

1. S. vulgare, Smith. Frond oblong-lanceolate from an auricled-heart-shaped base, entire or wavy-margined (7--18' long, 1--2' wide), bright green.--Shaded ravines and under limestone cliffs; central N. Y.; also in Canada and Tenn.; very rare. Aug. (Eu.)

11. CAMPTOSORUS, Link. WALKING-LEAF. (Pl. 18.)

Fruit-dots oblong or linear, as in Asplenium, but irregularly scattered on either side of the _reticulated veins_ of the simple frond, those next the midrib single, the outer ones inclined to approximate in pairs (so that their two indusia open face to face), or to become confluent at their ends, thus forming crooked lines (whence the name, from [Greek: kampto/s], _bent_, and [Greek: soro/s], for _fruit-dot_.)

1. C. rhizophyllus, Link. Fronds evergreen, sub-coriaceous, growing in tufts, spreading or procumbent (4--12' long), gradually narrowed from a cordate or auricled base to a long and slender acumination, which often roots at the end and forms a new plant.--Shaded rocks, especially calcareous rocks, N. Eng. to Minn., and southward to Kan. and Ala.--The auricles are sometimes greatly elongated, and even rooting; in another form they are lacking, as in the thinner leaved C. Sibiricus. July.

12. PHEGOPTERIS, Fee. BEECH FERN.

Fruit-dots small, round, naked (no indusium), borne on the back of the veins below the apex. Stipe continuous with the rootstock.--Our species have free veins and bright green membranaceous fronds, decaying in early autumn. (Name composed of [Greek: phego/s], an _oak_ or _beech_, and [Greek: pteri/s], _fern_.)

[*] _Fronds twice pinnatifid; pinnae all sessile, adnate to the winged rhachis._

1. P. polypodioides, Fee. Fronds triangular, _longer than broad_ (4--9' long), hairy on the veins, especially beneath; pinnae linear-lanceolate, _the lowest pair deflexed and standing forward_; their divisions oblong, obtuse, entire, the basal decurrent upon the main rhachis; fruit-dots all near the margin.--Damp woods; common northward. July.--Rootstock slender, creeping, bearing a few distant slender stalks, rather longer than the fronds. (Eu.)

2. P. hexagonoptera, Fee. Fronds triangular, _usually broader than long_ (7--12' broad), slightly pubescent and often finely glandular beneath; pinnae lanceolate; upper segments oblong, obtuse, toothed or entire, _those of the very large lowest pinnae elongated and pinnately lobed_, basal ones very much decurrent and forming a continuous many-angled wing along the main rhachis; fruit-dots near the margin; some also between the sinus and the midrib.--Rather open woods, New Eng. to Minn., and southward; common. July.--Larger and broader than the last, which it often closely resembles.

[*][*] _Fronds ternate, the three divisions petioled; rhachis wingless._

3. P. Dryopteris, Fee. _Fronds smooth_, broadly triangular (4--6' wide); the three triangular primary divisions _all widely spreading_, 1--2-pinnate; segments oblong, obtuse, entire or toothed; fruit-dots near the margin.--Rocky woods; common northward. July. (Eu.)

4. P. calcarea, Fee. _Fronds minutely glandular_ and somewhat rigid, _the lateral divisions ascending_; lowest inferior pinnae of the lateral divisions smaller in proportion than in the last species, which it otherwise closely resembles.--Iowa and Minn.; rare. July. (Eu.)

13. ASPIDIUM, Swartz. SHIELD FERN. WOOD FERN. (Pl. 19.)

Fruit-dots round, borne on the back or rarely at the apex of the veins. Indusium covering the sporangia, flat or flattish, scarious, orbicular and peltate at the centre, or round-kidney-shaped and fixed either centrally or by the sinus, opening all round the margin. Stipe continuous (not articulated) with the rootstock.--Our species have free veins and 1--3-pinnate fronds. (Name, [Greek: a)spi/dion], _a small shield_, from the shape of the indusium.)

Sec. 1. DRYOPTERIS. _Indusium reniform, or orbicular with a narrow sinus._

[*] _Veins simple or simply forked and straight; fronds annual, decaying in autumn, the stalks and slender creeping rootstocks nearly naked._

1. A. Thelypteris, Swartz. Fronds pinnate, lanceolate in outline; pinnae horizontal or slightly recurved, linear-lanceolate, deeply pinnatifid, _the lowest pairs scarcely smaller_; lobes oblong, entire, obtuse or appearing acute when in fruit from the _strongly revolute margins; veins mostly forked_, bearing the (soon confluent) fruit-dots near their middle; indusium minute, smooth and naked.--Marshes; common. Aug.--Stalk 1 deg. long or more, usually longer than the frond, which is of thicker texture than the next, and slightly downy. (Eu.)

2. A. Noveboracense, Swartz. Fronds pinnate, lanceolate in outline, _tapering both ways from the middle_; pinnae lanceolate, _the lowest 2 or more pairs gradually shorter and deflexed_; lobes flat, oblong, basal ones often enlarged and incised; _veins simple_, or forked in the basal lobes; fruit-dots distinct, near the margin; indusium minute, the margin glanduliferous.--Swamps and moist thickets; common. July.--Frond pale green, delicate and membranaceous, hairy beneath along the midribs and veins.

[*][*] _Veins, at least the lowest, more than once forked or somewhat pinnately branching; fruit-bearing veinlets often obscure or vanishing above the fruit-dot; fronds, at least the sterile ones, often evergreen; stalks and apex of the thickened rootstock scaly or chaffy, and often the main rhachis also._

[+] _Fronds small, pinnate; pinnae pinnatifid; indusia very large, persistent._

3. A. fragrans, Swartz. Fronds (4--12' high) glandular and aromatic, narrowly lanceolate, with linear-oblong pinnately-parted pinnae; their crowded divisions (2'' long) oblong, obtuse, toothed or nearly entire, nearly covered beneath with the very large thin imbricated indusia, which are orbicular with a narrow sinus, the margin sparingly glanduliferous and often ragged.--On rocks, especially near waterfalls, mountains of northern New Eng., west and northward.--Rootstock stout, nearly erect, densely chaffy, as are the crowded stipes and rhachis. (Asia, and barely reaching S. E. Eu.)

[+][+] _Large (1--21/2 deg. high), the fronds mostly twice pinnate with variously toothed and incised pinnules; indusia rather small, shrivelled in age, or deciduous._

4. A. spinulosum, Swartz. Stipes with a few _pale-brown deciduous scales_; frond ovate-lanceolate, twice pinnate; _pinnae oblique to the rhachis, elongated-triangular_, the lower pairs broadly triangular; pinnules set obliquely on the midribs, connected by a very narrow wing, oblong, acute, incisely serrate or pinnatifid with spinulosely-toothed lobes; _indusium_ smooth and _without marginal glands_.--In damp woods, New Eng. to Ky., and northward. July.--The common European type, rare in North America. (Eu.)

Var. intermedium, D. C. Eaton. _Scales_ of the stipe few, _brown with a darker centre_; frond broadly oblong-ovate, twice or often thrice pinnate; _pinnae spreading, oblong-lanceolate_, the lower unequally triangular-ovate; pinnules crowded, ovate-oblong, spreading, pinnately divided; the oblong lobes spinulose-toothed at the apex; _margin of the indusium denticulate and beset with minute stalked glands_.--Woods, everywhere.

Var. dilatatum, Hook. _Scales_ of the stipe large, _brown with a dark centre_; _frond broader, ovate or triangular-ovate_ in outline, oftenest thrice pinnate; pinnules lance-oblong, the lowest often much elongated; _indusium_ (in the North American plant) _smooth and naked_.--A dwarf state, fruiting when only 5--8' high, answers to var. dumetorum.--N. New Eng. to Minn., chiefly in mountain woods, and northward. (Eu.)

5. A. Boottii, Tuckerman. _Scales_ of the stipe _pale-brown_; fronds (1--21/2 deg. long) elongated-lanceolate in outline, somewhat narrowed at base; lowest pinnae triangular-ovate, the upper longer and narrower; pinnules oblong-ovate, sharply spinulose-serrate or the lower pinnatifid; _indusium minutely glandular_. (A. spinulosum, var. Boottii, of last ed. A. cristatum, var. uliginosum, _Milde_.)--Wet thickets and about ponds, New Eng. to Del. and Minn. July.--Sterile fronds much smaller and simpler than the fertile. (Eu.)

[+][+][+] _Large (2--4 deg. high); fronds once pinnate and the pinnae deeply pinnatifid, or nearly twice pinnate; fruit-dots not very near the margin; the indusium large, thinnish and flat, persistent._

6. A. cristatum, Swartz. _Frond linear-oblong or lanceolate in outline_ (1--2 deg. long); _pinnae short_ (2--3' long), _triangular-oblong_, or the lowest nearly triangular-ovate, from a somewhat heart-shaped base, acute, deeply pinnatifid; the _divisions (6--10 pairs) oblong_, very obtuse, finely serrate or cut-toothed, the lowest pinnatifid-lobed; _fruit-dots as near the midvein as the margin_; indusium round-reniform, the sinus mostly shallow, smooth and naked.--Swamps, etc.; common. July.--Stipes and the stout creeping rootstock bearing broad and deciduous chaffy scales. (Eu.)

Var. Clintonianum. _Frond in every way much larger_ (21/2--4 deg. long); _pinnae_ oblong-lanceolate, _broadest at base_ (4--6' long, 1--2' broad), deeply pinnatifid; the _divisions (8--16 pairs)_ crowded or distant, _linear-oblong_, obtuse, obscurely serrate or cut-toothed, the basal sometimes pinnately lobed; veins pinnately forking, the lowest anterior veinlets bearing the _fruit-dots near the midvein_; indusium orbicular with a shallow sinus, smooth and naked.--Swampy woods, New Eng. to N. J., N. Y. (_G. W. Clinton_, etc.), and westward. July.--Rootstock stout, creeping, chaffy (like the stipes) with large bright-brown scales. A showy fern, unlike any European form of A. cristatum, and often mistaken for A. Goldianum.

7. A. Goldianum, Hook. _Frond broadly ovate_, or the fertile ovate-oblong in outline (2--3 deg. long); _pinnae_ (6--9' long), oblong-lanceolate, _broadest in the middle_, pinnately parted; the _divisions (about 20 pairs) oblong-linear, slightly scythe-shaped_ (9--15'' long), serrate with appressed teeth; veins pinnately forking and bearing the _fruit-dots very near the midvein_; indusium very large, orbicular with a deep narrow sinus, smooth and without marginal glands.--Rich and moist woods, from Conn. to Ky., and northward. July.--A stately fern, often 4 deg. high, the fronds growing in a circle from a stout ascending chaffy rootstock, and decaying in autumn. Indusium with the sides of the sinus often overlapping, thus appearing to be round and entire as in Sec. Polystichum.

[+][+][+][+] _Large (1--3 deg. high); stipes very chaffy at base; fronds twice pinnate, but the upper pinnules confluent, some of the lower pinnatifid-toothed; fruit-dots rather large; indusium convex, without marginal glands, persistent._

8. A. Filix-mas, Swartz. Frond lanceolate in outline (1--3 deg. high); pinnae linear-lanceolate, tapering from base to apex; pinnules oblong, very obtuse, serrate at the apex and obscurely so at the sides, the basal incisely lobed, distinct, the upper confluent; fruit-dots nearer the midvein than the margin, and usually confined to the lower half of each fertile pinnule.--Rocky woods, N. Mich. to Dak. and Col.--Frond thickish but not surviving the winter. (Eu.)

9. A. marginale, Swartz. (Pl. 19, fig. 1, 2.) Frond evergreen, smooth, thickish and almost coriaceous, ovate-oblong in outline (1--2 deg. long); pinnae lanceolate, acuminate, slightly broadest above the base; pinnules oblong or oblong-scythe-shaped, crowded, obtuse or pointed, entire or crenately-toothed; fruit-dots close to the margin.--Rocky hillsides in rich woods; common, especially northward. Aug.

Sec. 2. POLYSTICHUM. _Indusium orbicular and entire, peltate, fixed by the depressed centre; fronds rigid and coriaceous, evergreen, very chaffy on the rhachis, etc.; pinnae or pinnules auricled at base on the upper side, crowded, the teeth or lobes bristle-tipped._

[*] _Fronds simply pinnate._

10. A. acrostichoides, Swartz. (CHRISTMAS FERN.) (Pl. 19, fig. 3, 4.) Frond lanceolate (1--21/2 deg. high), _stalked; pinnae linear-lanceolate_, somewhat scythe-shaped, half-halberd-shaped at the slightly stalked base, serrulate with appressed bristly teeth; _the fertile_ (upper) _contracted and smaller_, bearing contiguous fruit-dots near the midrib, which are confluent with age, covering the surface.--Var. INCISUM is a state with cut-lobed pinnae, a not unfrequent case in the sterile fronds; sometimes with all the tips fertile.--Common in rocky woods, especially northward. July.

11. A. Lonchitis, Swartz. Frond linear-lanceolate (9--20' high), _scarcely stalked, very rigid; pinnae broadly lanceolate-scythe-shaped, or the lowest triangular_, strongly auricled on the upper side, and wedge-truncate on the lower, densely spinulose-toothed (1' or less in length), copiously fruit-bearing; fruit-dots contiguous and near the margins.--Woods, southern shore of Lake Superior, and northward. (Eu.)

[*][*] _Fronds bipinnate._

12. A. aculeatum, Swartz, var. Braunii, Koch. _Fronds spreading_ (11/2--2 deg. long), oblong-lanceolate in outline, with a tapering base, the lower of the many pairs of oblong-lanceolate pinnae gradually reduced in size and obtuse; pinnules ovate or oblong, obtuse, truncate and almost rectangular at base, short-stalked, or the upper confluent, sharply toothed, beset with long and soft as well as chaffy hairs.--Deep woods, mountains of New Eng., N. Y., and Penn., and northward. (Eu.)

14. CYSTOPTERIS, Bernhardi. BLADDER FERN. (Pl. 19.)

Fruit-dots roundish, borne on the back of a straight fork of the free veins; the delicate indusium hood-like or arched, attached by a broad base on the inner side (toward the midrib) partly under the fruit-dot, early opening free at the other side, which looks toward the apex of the lobe, and is somewhat jagged, soon thrown back or withering away.--Tufted ferns with slender and delicate 2--3-pinnate fronds; the lobes cut-toothed. (Name composed of [Greek: ky/stis], _a bladder_, and [Greek: pteri/s], _fern_, from the inflated indusium.)

1. C. bulbifera, Bernh. (Pl. 19, fig. 1--3.) _Frond lanceolate, elongated_ (1--2 deg. long), 2-pinnate; the pinnae lanceolate-oblong, pointed, horizontal (1--2' long); the _rhachis and pinnae often bearing bulblets underneath, wingless_; pinnules crowded, oblong, obtuse, toothed or pinnatifid; indusium short, truncate on the free side.--Shaded ravines, not rare from N. Eng. to Ark., commoner on calcareous rocks. July.--Specimens from Tenn. and Ark. have sometimes shorter fronds and few or no bulblets, indicating an approach to the next species.

2. C. fragilis, Bernh. _Frond oblong-lanceolate_ (4--8' long, besides the brittle stalk which is fully as long), 2--3-pinnate; the pinnae and _pinnules_ ovate or lanceolate in outline, irregularly pinnatifid or cut-toothed, mostly acute, _decurrent on the margined or winged rhachis_; indusium tapering or acute at the free end.--Shaded cliffs and rocky woods; common and greatly varying in the shape and cutting of the pinnules. July. (Eu.)

15. ONOCLEA, L. (Pl. 16 and 19.)

Sporangia borne on elevated receptacles, forming roundish sori imperfectly covered by very delicate hood-shaped indusia attached to the base of the receptacles. Fertile fronds erect, rigid, with contracted pod-like or berry-like divisions at first completely concealing the sporangia, and at last, when dry and indurated, cracking open and allowing the spores to escape. Sterile fronds foliaceous. Rootstocks creeping and constantly forming new plants. (Name apparently from [Greek: o)/nos], _a vessel_, and [Greek: klei/o], _to close_, from the singularly rolled up fructification.)

Sec. 1. ONOCLEA proper. _Sterile frond with anastomosing veins._

1. O. sensibilis, L. (SENSITIVE FERN.) (Pl. 19, fig. 1, 2.) Fronds scattered; the sterile ones long-stalked (2--15' long), triangular-ovate, pinnatifid into a few oblong-lanceolate sinuately lobed or nearly entire segments; veins reticulated with fine meshes; fertile fronds contracted, closely bipinnate, the pinnules rolled up into berry-like bodies.--Moist meadows and thickets, very common and variable. July.--Imperfectly fertile fronds sometimes occur, with the still foliaceous pinnae cut into obovate segments with free veins and abortive sori; the so-called var. OBTUSILOBATA.

Sec. 2. STRUTHIOPTERIS. _Sterile frond with free veins._

2. O. Struthiopteris, Hoffmann. (Pl. 16, fig. 1--5.) Fronds growing in a crown; sterile ones short-stalked (2--10 deg. high), broadly lanceolate, narrowed toward the base, pinnate with many linear-lanceolate, pinnatifid pinnae; veins free, the veinlets simple; fertile frond shorter, pinnate with pod-like or somewhat necklace-shaped pinnae. (Struthiopteris Germanica, _Willd._)--Alluvial soil, common northward. July.--The rootstock sends out slender underground stolons, which bear fronds the next year. (Eu.)

16. WOODSIA, R. Brown. (Pl. 19.)

Fruit-dots round, borne on the back of simply-forked free veins; the very thin and often evanescent indusium attached by its base all around the receptacle, _under_ the sporangia, either small and open, or else early bursting at the top into irregular pieces or lobes.--Small and tufted pinnately-divided ferns. (Dedicated to _Joseph Woods_, an English botanist.)

[*] _Stalks obscurely articulated some distance from the base; fronds chaffy or smooth, never glandular; indusium divided nearly to the centre into slender hairs which are curled over the sporangia._

1. W. Ilvensis, R. Brown. _Frond oblong-lanceolate_ (2--6' long by 12--18'' wide), smoothish and green above, _thickly clothed underneath as well as the stalk with rusty bristle-like chaff_, pinnate; the pinnae crowded, oblong, obtuse, sessile, pinnately parted, _the numerous crowded segments oblong_, obtuse, obscurely crenate; the fruit-dots near the margin, somewhat confluent when old.--Exposed rocks; common, especially northward, and southward in the Alleghanies. June. (Eu.)

2. W. hyperborea, R. Brown. Frond narrowly oblong-lanceolate (2--6' long by 8--12'' wide), smooth above, sparingly paleaceous-hirsute beneath, pinnate; the pinnae triangular-ovate, obtuse, pinnately lobed, the lobes few and nearly entire; fruit-dots rarely confluent.--Mountain ravines, northern Vt. and N. Y., and northward; rare. (Eu.)

3. W. glabella, R. Brown. (Pl. 19, fig. 1--3.) _Smooth and naked throughout; frond linear_ and very delicate (2--5' high), pinnate; _pinnae roundish-ovate_, the lower ones rather remote (2--4'' long), obtuse, crenately lobed; fruit-dots scanty; the hairs of the indusium fewer than in the last two species.--On moist mossy rocks, mountains of northern New Eng., north and westward. First found at Little Falls, N. Y., by _Dr. Vasey_. (Eu.)

[*][*] _Stalks not articulated; fronds never chaffy, often glandular-pubescent._

[+] _Indusium of a few broad segments, at first covering the sorus completely._

4. W. obtusa, Torr. (Pl. 19, fig. 4, 5.) Frond broadly lanceolate, minutely glandular-hairy (6--12' high), pinnate, or nearly twice pinnate; pinnae rather remote, triangular-ovate or oblong (1--2' long), bluntish, pinnately parted; segments oblong, obtuse, crenately toothed, the lower pinnatifid with toothed lobes; veins forked, and bearing the fruit-dots on or below the minutely toothed lobes; indusium at length splitting into several spreading jagged lobes.--Rocky banks and cliffs; not rare.

[+][+] _Indusium entirely concealed beneath the sorus, divided into very narrow segments or reduced to minute hairs._

5. W. Oregana, D. C. Eaton. Smooth, with fronds (2--8' high, 8--12'' wide) elliptical-lanceolate, pinnate, the fertile ones tallest; pinnae triangular-oblong, obtuse, pinnatifid; segments oblong or ovate, obtuse, finely toothed, and in larger fronds incised; fruit-dots near the margin; indusium very small, divided almost to the centre into a few necklace-like-jointed cilia.--Crevices of rocks, south shore of Lake Superior (_Robbins_), and westward.

6. W. scopulina, D. C. Eaton. Much like the last, but the rather larger fronds puberulent beneath with minute jointed hairs and stalked glands; indusium deeply cleft into narrow segments ending in jointed hairs.--Rocky places, Minn., southward and westward.

17. DICKSONIA, L'Her. (Pl. 17.)

Fruit-dots small, globular, marginal, each placed on the apex of a free vein or fork; the sporangia borne on an elevated globular receptacle, enclosed in a membranaceous cup-shaped indusium which is open at the top, and on the outer side partly adherent to a reflexed toothlet of the frond. (Named for _James Dickson_, an English Cryptogamic botanist.)

1. D. pilosiuscula, Willd. Fronds minutely glandular and hairy (2--3 deg. high), ovate-lanceolate and acuminate in outline, pale green, very thin, with strong chaffless stalks rising from slender extensively creeping naked root-stocks, mostly bipinnate; primary pinnae lanceolate, pointed, the secondary pinnatifid into oblong and obtuse cut-toothed lobes; fruit-dots minute, each on a recurved toothlet, usually one at the upper margin of each lobe. (D. punctilobula, _Kunze_.)--Common in moist and shady places, from New Eng. to Minn.--Frond sweet-scented in drying.

18. TRICHOMANES, L. FILMY FERN.

Sporangia with a transverse entire ring, sessile on a cylindrical receptacle which is produced from the end of a vein and enclosed in a funnel-form or cup-shaped involucre of the same substance with the frond. Fronds very thin and pellucid, often consisting of a single layer of cells. (An ancient Greek name for some fern.)

1. T. radicans, Swartz. Fronds very delicate, oblong-lanceolate in outline (4--8' long, 6--18'' wide), bipinnatifid; rhachis narrowly winged; pinnae triangular-ovate, the divisions toothed or again lobed; involucres tubular-funnel-shaped, margined, the mouth truncate; receptacle often much exserted.--On moist and dripping sandstone cliffs, Ky., and southward; rare.--Though the fronds are so very delicate, yet they survive for several years; they begin to fruit the second or third year, and thereafter the receptacle continues to grow and to produce new sporangia at its base. (Eu.)

19. SCHIZAEA, Smith. (Pl. 20.)

Sporangia large, ovoid, striate-rayed at the apex, opening by a longitudinal cleft, naked, vertically sessile in a double row along the single vein of the narrow divisions of the pinnate (or radiate) fertile appendages to the slender and simply linear, or (in foreign species) fan-shaped or dichotomously many-cleft fronds (whence the name, from [Greek: schi/zo], _to split_).

1. S. pusilla, Pursh. Sterile fronds linear, very slender, flattened and tortuous; the fertile ones equally slender (1/4'' wide), but taller (3--4' high), and bearing at the top the fertile appendage, consisting of about 5 pairs of crowded pinnae (each 1--11/2'' long).--Low grounds, pine barrens of N. J.; very local. Sept. (Also in Nova Scotia and Newf.)

20. LYGODIUM, Swartz. CLIMBING FERN. (Pl. 20.)

Fronds twining or climbing, bearing stalked and variously lobed (or compound) divisions in pairs, with mostly free veins; the fructification on separate contracted divisions or spike-like lobes, one side of which is covered with a double row of imbricated hooded scale-like indusia, fixed by a broad base to short oblique veinlets. Sporangia much as in Schizaea, but oblique, fixed to the veinlet by the inner side next the base, one or rarely two covered by each indusium. (Name from [Greek: lygo/des], _flexible_.)

1. L. palmatum, Swartz. Very smooth; stalks slender, flexile and twining (1--3 deg. long), from slender running rootstocks; the short alternate branches or petioles 2-forked; each fork bearing a round-heart-shaped palmately 4--7-lobed frondlet; fertile frondlets above, contracted and several times forked, forming a terminal panicle.--Low moist thickets and open woods, Mass. to Va., Ky., and sparingly southward; rare. Sept.

21. OSMUNDA, L. FLOWERING FERN. (Pl. 20.)

Fertile fronds or fertile portions of the frond destitute of chlorophyll, very much contracted, and bearing on the margins of the narrow rhachis-like divisions short-pedicelled and naked sporangia; these are globular, thin and reticulated, large, opening by a longitudinal cleft into two valves, and bearing near the apex a small patch of thickened oblong cells, the rudiment of a transverse ring.--Fronds tall and upright, growing in large crowns from thickened rootstocks, once or twice pinnate; veins forking and free. Spores green. (_Osmunder_, a Saxon name of the Celtic divinity, Thor.)

[*] _Sterile fronds truly bipinnate._

1. O. regalis, L. (FLOWERING FERN.) Very smooth, pale green (2--5 deg. high); sterile pinnules 13--25, varying from oblong-oval to lance-oblong, finely serrulate, especially toward the apex, otherwise entire, or crenately lobed toward the rounded, oblique and truncate, or even cordate and semi-auriculate base, sessile or short-stalked (1--2' long); the fertile racemose-panicled at the summit of the frond.--Swamps and wet woods; common. The cordate pinnules sometimes found here are commoner in Europe. May, June. (Eu.)

[*][*] _Sterile fronds once pinnate; pinnae deeply pinnatifid; the lobes entire._

2. O. Claytoniana, L. (Pl. 20, fig. 1--3.) Clothed with loose wool when young, soon smooth; _fertile fronds taller than the sterile_ (2--4 deg. high); pinnae oblong-lanceolate, with oblong obtuse divisions; _some (2--5 pairs) of the middle pinnae fertile_, these entirely pinnate; sporangia greenish, turning brown.--Low grounds, common. May.--Fruiting as it unfolds.

3. O. cinnamomea, L. (CINNAMON FERN.) Clothed with rusty wool when young; _sterile fronds tallest_ (at length 3--5 deg. high), smooth when full grown, the lanceolate pinnae pinnatifid into broadly oblong obtuse divisions; _fertile fronds separate_, appearing earlier from the same rootstock and soon withering (1--2 deg. high), contracted, twice pinnate, covered with the cinnamon-colored sporangia.--Var. FRONDOSA is a rare occasional state, in which some of the fronds are sterile below and more sparsely fertile at their summit, or rarely in the middle.--Swamps and low copses, everywhere. May.

ORDER 132. OPHIOGLOSSACEAE. (ADDER'S-TONGUE FAMILY.)

Leafy and often somewhat fleshy plants; the leaves (_fronds_) simple or branched, often fern-like in appearance, erect in vernation, developed from underground buds formed either inside the base of the old stalk or by the side of it, and bearing in special spikes or panicles rather large subcoriaceous bivalvular sporangia formed from the main tissue of the fruiting branches. Prothallus underground, not green, monoecious.--A small order, separated from Ferns on account of the different nature of the sporangia, the erect vernation, etc.

1. Botrychium. Sporangia in pinnate or compound spikes, distinct. Veins free.

2. Ophioglossum. Sporangia cohering in a simple spike. Veins reticulated.

1. BOTRYCHIUM, Swartz. MOONWORT. (Pl. 20.)

Rootstock very short, erect, with clustered fleshy roots (which are full of starch, in very minute, irregular granules!); the base of the naked stalk containing the bud for the next year's frond; frond with an anterior fertile and a posterior sterile segment; the former mostly 1--3-pinnate, the contracted divisions bearing a double row of sessile naked sporangia; these are distinct, rather coriaceous, not reticulated, globular, without a ring, and open transversely into two valves. Sterile segment of the frond ternately or pinnately divided or compound; veins all free. Spores copious, sulphur-color. (Name a diminutive of [Greek: bo/trys], _a cluster of grapes_, from the appearance of the fructification.)

Sec. 1. BOTRYCHIUM proper. _Base of the stalk containing the bud completely closed; sterile segment more or less fleshy; the cells of the epidermis straight._

[*] _Sterile portion of the frond sessile or nearly so at or above the middle of the plant. Plants small._

1. B. Lunaria, Swartz. _Sterile segment_ nearly sessile, borne near the middle of the plant, _oblong, simply pinnate with 5--15 lunate or fan-shaped_ very obtuse crenate, incised or nearly entire, _fleshy divisions_, more or less excised at the base on the lower or on both sides, the veins radiating from the base and repeatedly forking; fertile segment panicled, 2--3-pinnate.--N. Eng. to Lake Superior, and northward; rare.--Very fleshy, 4--10' high. (Eu.)

2. B. simplex, Hitchcock. Fronds small (2--4', rarely 5--6' high), _the sterile segment short-petioled from near the middle of the plant, thickish_ and fleshy, simple and roundish, or _pinnately 3--7-lobed_; the lobes roundish-obovate, nearly entire, decurrent on the broad and flat indeterminate rhachis; _the veins all forking from the base_; fertile segment simple or 1--2-pinnate.--Maine to N. Y., Minn., and northward; rare. (Eu.)

3. B. lanceolatum, Angstroem. Fronds small (3--10' high); _the sterile segment closely sessile at the top of the_ long and slender common _stalk_, scarcely fleshy, _triangular, ternately twice pinnatifid; the acute lobes_ lanceolate, incised or toothed; veinlets forking from a _continuous midvein_; fertile part 2--3-pinnate.--N. Eng. and N. J. to Ohio and Lake Superior. July--Aug. (Eu.)

4. B. matricariaefolium, Braun. Fronds small (3--10' high); _the sterile segment nearly sessile at the top of the_ long and slender _common stalk_, moderately fleshy, _ovate or triangular_, varying from pinnate to bipinnatifid; _the lobes oblong-ovate and obtuse; midvein dissipated_ into forking veinlets; fertile part 2--3-pinnate.--Same range as the last. June, July. (Eu.)

[*][*] _Sterile portion of the frond long-stalked; the common stalk short in proportion to the size of the plant. Plants usually larger._

5. B. ternatum, Swartz. (Pl. 20.) _Plant very fleshy_ (4--16' high), sparsely hairy; _sterile segment long-petioled_ from near the base of the plant, broadly triangular, _ternate and variously decompound with stalked divisions_; ultimate segments varying from roundish-reniform and sub-entire to ovate-lanceolate and doubly incised; fertile segment erect, 2--4-pinnate.--The following varieties pass into each other:--Var. AUSTRALE; frond ample; ultimate segments rhomboid-ovate with a denticulate margin.--Var. INTERMEDIUM; frond of moderate size; ultimate segments as in var. australe. (B. lunarioides, of last ed.)--Var. RUTAEFOLIUM; frond small; ultimate segments few, ovate and semicordate.--Var. LUNARIOIDES; frond small; ultimate segments roundish-reniform.--Var. OBLIQUUM; frond moderate; ultimate segments obliquely lanceolate, denticulate or toothed.--Var. DISSECTUM; segments dissected into innumerable narrow lobes or teeth.--Pastures and hillsides, sometimes in dry woods, rather common, especially vars. intermedium and obliquum.--Var. rutaefolium occurs in Europe.

Sec. 2. OSMUNDOPTERIS. _Base of the stalk containing the bud open along one side; sterile segment membranaceous; the cells of the epidermis flexuous._

6. B. Virginianum, Swartz. _Fronds tall and ample; sterile segment sessile above the middle of the plant_, broadly triangular, thin and membranaceous, _ternate_; the short-stalked _primary divisions once or twice pinnate_, and then once or twice pinnatifid; the oblong lobes cut-toothed toward the apex; _veins forking from a midvein_; fertile part 2--3-pinnate.--Rich woods; common.--Plant 1--2 deg. high, or often reduced to a few inches, in which case it is B. gracile, _Pursh._ June, July. (Eu.)

2. OPHIOGLOSSUM, L. ADDER'S-TONGUE. (Pl. 20.)

Rootstock erect, fleshy and sometimes tuberous, with slender fleshy roots which are sometimes proliferous; bud placed by the side of the base of the stalk; fronds with anterior and posterior segments as in Botrychium, but the coriaceous sporangia connate and coherent in two ranks on the edges of a simple spike. Sterile segment fleshy, simple in our species; the veins reticulated. Spores copious, sulphur-yellow. (Name from [Greek: o)/phis], _a serpent_, and [Greek: glo~ssa], _tongue_.)

1. O. vulgatum, L. Fronds from a slender rootstock (2--12' high), mostly solitary; sterile segment sessile near the middle of the plant, ovate or elliptical (1--3' long); midvein indistinct or none; veins forming small meshes enclosed in larger ones.--Bogs and pastures; not common. July. (Eu.)

ORDER 133. LYCOPODIACEAE. (CLUB-MOSS FAMILY.)

Low plants, usually of moss-like aspect, with elongated and often much branched stems covered with small lanceolate or subulate, rarely oblong or rounded, persistent entire leaves; the sporangia 1--3-celled, solitary in the axils of the leaves, or on their upper surface, when ripe opening into two or three valves, and shedding the numerous yellow spores, which are all of one kind.--The Order, as here defined, consists mainly of the large genus

1. LYCOPODIUM, L. CLUB-MOSS. (Pl. 21.)

Spore-cases coriaceous, flattened, usually kidney-shaped, 1-celled, 2-valved, mostly by a transverse line round the margin, discharging the subtile spores in the form of a copious sulphur-colored inflammable powder.--Perennials, with evergreen one-nerved leaves, imbricated or crowded in 4--16 ranks. (Name compounded of [Greek: ly/kos], _a wolf_, and [Greek: pou~s], _foot_, from no obvious resemblance.)

Sec. 1. _Spore-cases in the axils of the ordinary (dark green and shining, rigid, lanceolate, about 8-ranked) leaves._

1. L. Selago, L. Stems erect and rigid, dichotomous, forming a level-topped cluster (3--6' high); _leaves uniform_, crowded, ascending, glossy, pointed, entire or denticulate; sporangia in the axils of unaltered leaves.--Mountain-tops, Maine to Lake Superior, and northward.--The leaves of this and the next species often bear little gemmae, with the lower bracts pointed, and the 2--3 uppermost broadly obovate and fleshy, as figured in 1768 by Dillenius. These gemmae fall to the ground and their axis grows into the stem of a new plant, as specimens collected in 1854 show very plainly. (For their true nature see Sachs' Lehrbuch, Engl. trans., p. 411.)

2. L. lucidulum, Michx. Stems assurgent, less rigid, dichotomous (6--12' long); leaves pointed, toothed, at first spreading, then deflexed, arranged, in alternate zones of shorter and longer leaves, the shorter leaves more frequently bearing sporangia in their axils; proliferous gemmae usually abundant.--Cold, damp woods; common northward. Aug.

Sec. 2. _Spore-cases only in the axils of the upper (bracteal) leaves, thus forming a spike._

[*] _Leaves of the creeping sterile and of the upright fertile stems or branches and those of the simple spike nearly alike, many-ranked._

3. L. inundatum, L. _Dwarf_; creeping sterile stems forking, flaccid; the fertile solitary (1--4' high), bearing a short thick spike; _leaves lanceolate or lance-awl-shaped, acute_, soft, spreading, _mostly entire_, those of the prostrate stems curving upward.--Var. BIGELOVII, Tuckerm., has fertile stems 5--7' high, its leaves more awl-shaped and pointed, sparser and more upright, often somewhat teeth-bearing.--Sandy bogs, northward, not common; the var., eastern New Eng. to N. J., and southward. Aug. (Eu.)

4. L. alopecuroides, L. _Stems stout_, very densely leafy throughout; the sterile branches recurved-procumbent and creeping; the fertile of the same thickness, 6--20' high; _leaves narrowly linear-awl-shaped, spinulose-pointed, spreading, conspicuously bristle-toothed below the middle; those of the cylindrical spike with long setaceous tips_.--Pine-barren swamps, N. J. to Va., and southward. Aug., Sept.--Stems, including the dense leaves, 1/2' thick; the comose spike, with its longer spreading leaves, 3/4--1' thick.

[*][*] _Leaves (bracts) of the catkin-like spike scale-like, imbricated, yellowish, ovate or heart-shaped, very different from those of the sterile stems and branches._

[+] _Spikes sessile (i.e. branches equally leafy to the top), single._

5. L. annotinum, L. Much branched; _stems prostrate and creeping_ (1--4 deg. long); _the ascending branches similar_ (5--8' high), sparingly forked, the sterile ones making yearly growths from the summit; _leaves equal, spreading_, in about 5 ranks, rigid, lanceolate, pointed, minutely serrulate (pale green); spike solitary, oblong-cylindrical, thick.--Var. PUNGENS, Spring, is a reduced sub-alpine or mountain form, with shorter and more rigid pointed erectish leaves.--Woods; common northward; the var. on the White Mountains, with intermediate forms around the base. July. (Eu.)

6. L. obscurum, L. Rootstock cord-like, subterranean, bearing scattered, erect, tree-like stems dividing at the summit into several densely dichotomous spreading branches; leaves linear-lanceolate, decurrent, entire, acute, 6-ranked, those of the two upper and two lower ranks smaller and appressed, the lateral ones incurved spreading; spikes 1--10, erect, mostly sessile; bracts scarious-margined, broadly ovate, abruptly apiculate.--Var. DENDROIDEUM (L. deudroideum, _Michx._) has all the leaves alike and incurved spreading.--Moist woods. Aug.--Remarkable for its tree-like appearance.